Enrichment of provitamin A content in durum wheat grain by suppressing β-carotene hydroxylase 1 genes with a TILLING approach

• Published in: Theoretical and applied genetics Vol. 134; no. 12; pp. 4013 - 4024
• Main Authors: Garcia Molina, Maria Dolores, Botticella, Ermelinda, Beleggia, Romina, Palombieri, Samuela, De Vita, Pasquale, Masci, Stefania, Lafiandra, Domenico, Sestili, Francesco
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer Berlin Heidelberg 01.12.2021; Springer Nature B.V
• Subjects: Agriculture; Biochemistry; Biomedical and Life Sciences; Biosynthesis; Biotechnology; Carbohydrates; Carotenoids; Edible Grain - chemistry; Edible Grain - genetics; Ferredoxin hydrogenase; Food, Fortified; Gene Knockout Techniques; Genomes; Genotype; Genotypes; Grain; Hydroxylase; Life Sciences; Metabolic Engineering; Micronutrients; Mixed Function Oxygenases - genetics; Mutants; Nutrient deficiency; Original Article; Pasta; Phylogeny; Plant Biochemistry; Plant Breeding; Plant Breeding/Biotechnology; Plant Genetics and Genomics; Provitamins - biosynthesis; Public health; Seeds - chemistry; Triticum - chemistry; Triticum - genetics; Triticum durum; Violaxanthin; Vitamin A; Vitamin A - biosynthesis; Xanthophylls; Zeaxanthin; Zeaxanthins - biosynthesis; β-Carotene
• ISSN: 0040-5752; 1432-2242
• DOI: 10.1007/s00122-021-03944-6

Key message The suppression of the HYD-1 gene by a TILLING approach increases the amount of β-carotene in durum wheat kernel. Vitamin A deficiency is a major public health problem that affects numerous countries in the world. As humans are not able to synthesize vitamin A, it must be daily assimilated along with other micro- and macronutrients through the diet. Durum wheat is an important crop for Mediterranean countries and provides a discrete amount of nutrients, such as carbohydrates and proteins, but it is deficient in some essential micronutrients, including provitamin A. In the present work, a targeting induced local lesions in genomes strategy has been undertaken to obtain durum wheat genotypes biofortified in provitamin A. In detail, we focused on the suppression of the β-carotene hydroxylase 1 ( HYD1 ) genes, encoding enzymes involved in the redirection of β-carotene toward the synthesis of the downstream xanthophylls (neoxanthin, violaxanthin and zeaxanthin). Expression analysis of genes involved in carotenoid biosynthesis revealed a reduction of the abundance of HYD1 transcripts greater than 50% in mutant grain compared to the control. The biochemical profiling of carotenoid in the wheat mutant genotypes highlighted a significant increase of more than 70% of β-carotene compared to the wild-type sibling lines, with no change in lutein, α-carotene and zeaxanthin content. This study sheds new light on the molecular mechanism governing carotenoid biosynthesis in durum wheat and provides new genotypes that represent a good genetic resource for future breeding programs focused on the provitamin A biofortification through non-transgenic approaches.